Sheet-surfacing apparatus



A. L. HARRINGTON SHEET SURFACING APPARATUS May 29, 1928. 7 1,671,718

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A. L. HARRINGTON SHEET SURFAC ING APPARATUS May 29, 1928.

9 Sheets-Sheet 4 Filed May 16, 1927 INVENTOR A. L. HARRINGTON SHEETSURFACING APPARATUS May 29, 1928.

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May 29, 1928. 1,671,718 I A. L. HARRINGTON SHEET suamcme APPARATUS FiledMay 16, 1927 9 Sheets-Sheet 6 I 1 F4' .5 165 J 174 May 29, 1928.1,671,718 I A. L. HARRINGTON 1 SHEET SURFAC INC1 APPARATUS Filed May 16,1927 9 Sheets-Sheet 7 I 165 1 l l i 2 I I l I 1* l 1 I i I i 1 I 1 L 1'J INVENTOR 9 Sheets-Sheet 8 Filed May 16, 1927 .ZJQ,

A. L. HARRINGTON SHEET SURFACING APPARATUS May 29, 1928.

May 29, 1928.

A. L. HARRINGTON SHEET SURFACING APPARATUS Filed May 16, 1927 9Sheets-Sheet 9 m T N I V m Patented May 29, 1928.

UNITED STATES 1,671,718 PATENT OFI-lCE..

ALFRED Ii. HARRINGTON, OI CARNEGIE, PHNSYLVAIIA, AISIGIOB IO PLATE GLASSCOMPANY, A. CORPORATION 01' PENNSYLVANIA.

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The invention relates to sheet surfacing machines and particularly tothose for use. in surfacin sheet glass in a straight away or straightline operation, in which the glass sheets upon a train of tables or carsare passed beneath a series of grinding and pol- 1Shi1'1 machines. Insuch an operation, there may e a series of 24 or more grinding machinesfollowed b 48 or more olishing machines, and it is t e object of tliepresent invention to provide improved means for controlling theoperation of these machines, the raising and lowering movements of therunners and the operation of the drive of the cars or tables, so that,(1) the danger of breakage of the glass u on the tables is reduced to aminimum; 2) the starting and stopping of the'a' paratus is facilitatedand loss of time avoi ed; (3) the load upon the electrical circuits isproperly distributed; (43 and the safety of the apparatus is increaseCertain embodiments of the invention are illustrated in the accompanyingdrawings, wherein:

Figure 1 is a plan view of the apparatus, a small number only of theindividual inding and polishing machines being s own. Fig. 2 is alongitudinal section on the line II-II of Fig. 1. Fig. 3 is a section onthe so line IIIIII of Fig. 1 on an enlarged scale. Fig. 4 is a sectionon an enlarged scale through the casing of the air valve and itsmagnetic control. Figs. 5 5 and 5 together show the wiring diagram ofthe system. Fig. 6 is a detail of one of the runner supporting leversand the switches operated thereby. Figs. 7, 8, 9, 10 and 11 are enlargedviews of different parts of the apparatus shown in Figs. 5, 5 and 5",such 'views being diagrammatic in character. And Fig. 12 shows amodification, involving a different prime mover for raising the runner,and the wiring diagram therefor.

Referring to Figs. 1, 2 and 3, A, B, C, D, E and F are a plurality ofsurfacin machines arranged in series above the trac 1, the machines Aand B bein grinding machines, and C, D, E and 15 polishing machines. Asa matter of fact, each machine represents a group of about 12 machines,it being impracticable to illustrate such a large number of units andtheir wiring diagrams, as will be apparent later when Figs. 5, 5 and 5are consi ered. It will be understood that all the machines of eachgroup have the same wiring control and 0 rate simultaneously, so that aconsideration of a representative machine of each group will make clearthe entire arrangement.

Mounted on the track 1 are a series of tables 2, 2,2, etc. placed end toend in abutting relation and provided on their lower sides with theracks 3, by. means of which the tables are fed continuously forward fromleft to ri ht (Fig. 2 tables being supplied at the le t hand on of thesystem as they are removed from the right hand end thereof. The glasssheets to be surfaced are embedded in plaster upon the tops of thetables so that the series of cars constitute in effect a continuousgrinding table. The racks are driven by two spur wheels 4, 4 at the lefthand end of the track, such gears belng lin turn operated from themotors G and through the spur gears 5, 5 and suit able reduction gearingin the casing 6, 6. Either motor is suflicient to move the tablesforward, the use of the two being merely a matter of precaution to takecare of an emergenc which might arise due to the failure 0 a singledrive motor.

At the end of the track toward which the cars are moving (Fig. 2)l is afriction brake comprising a shaft 4" aving a .pinion' in engagement withthe racks 3, a wheel 4" keyed to the shaft, and a brake band 4 passingaround the wheel. This device provides a yielding resistance retardingthe movement of the tables so that any danger of the tables becomingseparated is avoided and the rate of their movement beneath thesurfacing machines is made more even and uniform.

The construction of one of the surfacing units, preferably employed,will be seen by reference to Fig. 3, which shows the first grindingmachine A of the series. The movable parts are supported upon aframework 7, which carries the casting 8. Al tubular casing 9 carriesthe runner shaft 10, which in turn'supports the runner 11. The casing,and with it the runner shaft and runner, are guided for verticalmovement by the lever 12 and the arm 13 pivoted upon the ins 14 and 15mounted in the casting 8. he lever and arm engage the trunnions 16 and17 on the casing 9, the lever 12 serving to support such casing and moveit up and down, as later described. A motor A is supported on the up erend of the casin 9 and serves to drive t e runner shaft 10 tl rough theintermediary of suitable reduction gearing in the casings 18 and 19.

The lever 12 carries at its outer end the yoke 20, in which is guidedfor vertical movement the block 21, through which extends a rod 22threaded at its lower end and carrying the adjusting hand wheel 23. Thelower end of the yoke 20 supports the base of the coil spring 24, sothat when the rod 22 is moved downward, moving the block 21 downward,the spring is compressed, thus tending to counterbalance the wei ht ofthe grinding unit on the other end 0 the lever 12. The wheel 23, whichis threaded on the rod 22, is held against upward movement by means of asleeve 25 ivoted in brackets 26 secured to the lower anges of one of theframe members. The hand wheel 23, in connection with the rod 22 andsprin 24 thus serve as a means of counterweig ting the grinding unit toany desired extent de ending upon the grinding conditions, an alsoserves as a means for lifting the runner entirely out of contact withthe glass when this becomes necessary.

Mounted above the lever 12 of each of the grinding and polishingmachines is an air lift for the grinding unit carried by the lever. Thislift consists in each case of a c linder 27 secured to the framework oft e machine, together with a suitable piston in the cylinder providedwith a piston rod 28 pivoted at its lower end to a bracket clamped tothe lever arm. Alongside each piston is an air storage cylinder 29having pipe connections 30 and 31 leadin to the up or end of thecylinder 27 via t e valve casin 32, the flow from which c linder iselectrically controlled, as hereina ter more fully explained. Thestorage cylinders are supplied with air under pressure from an air line33 extending longitudinally of the series of grinding mac ines andprovided with outlet branches 34 leading to the various storagecylinders. Provision of a storage cylinder adjacent each of the liftsinsures a suflicient quantity of air to operate the cylinders promptlyand in unison.

The electrically controlled valve mechanism in the casing 32 will beseen by reference to Fig. 4. A magnet winding I is provided in fixedposition in the casing, adapted, when energized, to cause the downwardmovement of the tubular armature 35 slidably mounted in the upper end ofthe This armature en ages at its lower end a rod 36 slidably guifed in asleeve 37, which acts as the core to the winding I. Mounted in the lowerend of this rod 36 is a valve stem 38 carrying the valves 39 and 40, thevalve 39 being normally held closed the valve 40 open by means of thecoil spring 41 located beneath the valve. 39.

of its piston 1s vented to the atmosp When the valve is in thisposition, the chamber of the cylinder 27 on the up er side ere via thepi e 31, the passage 42 and t e outlet 43. when current is suppliedthrough the magnet winding I, the downward movement of the armature 35causes the valve 40 to close and the valve 39 to open. This closes theoutlet from the cylinder 27 through the passage 43 and admits a sup lyof air from the storage cylinder 29 via t 1e pipe 30, the assage 42, andthe ipe 31. he up and own movement of t e arm 12 also opens and closes apair of other switches 1- and a in the casin 43, whose functions are setforth later erein in connection with the description of the wiring diaram.

Fi 5, 5 and 5 of the rawing shows the e ectrical apparatus for thesystem. The complete wiring diagram of only two of the mac ines isshown, but the arrangement of all the others will be readily apparentfrom a consideration of the two. The two selected are the first andthird of the series; viz., A and C. It will be further understood thatthese two machines are representative of two groups of machines, eachconsisting of about 12 or more machines. The wiring for all the membersof each grou is a duplication of that of the individual machine of thegroup, as illustrated and described.

The startin and stopping of the entire system, inclu ing the motorswhich drive t e tables and those for driving all the run ners iscontrolled from the panel J. This panel includes the start button K, thestop utton L, the multiple switch M, and the thermo-relay switch N,which 0 ens when the flow of current through eit er of the heating coilsN N increases beyond a certain point. A part of this panel is shown onan enlarged scale in Fi 7. As here shown, the parts of the switc M areyieldingly held in the osition shown by the spring 44, thus holding theswitch arms 45 to 49, which are attached tothe solenoid bar open, andthe arm 50 closed. When current is passed through the coil 52, the baris pulled to the left closing the switches 45 to 49 and openin theswitch 50. As hereinafter more ful y described, the pressing down of thepush button K causes current to pass through the coil 52, thus movingthe time and insures that the runners shall be rotating and the tablesmovin therebeneath before the runners enga e the glass. The arms 53, 53of the switc i N are yieldingly held closed by the bi-metallic strips54, 54 fixed at their outer ends, such strips being located adjacent theheating coils N, N. The arms 53, 53 lie in the same circuit as the coil52 and are proi'ided with s rings 55, 55 tending to open them. When t ecurrent through the heating'coils rises above a predetermined point, theheat from the coils causes the arms 54, 54 to bend or warp, re: leasingthe ends of the arms 53, 53 so that they open, thus interrupting theflow of current through the arms and through the coil 52 so that theswitch M opens, interrupting the operation of the entire system-Thermo-relays of this type are well known in the art so that nodetailed showing or explanation is necessary.

he sequence control panel 0 includes the multiple switch P, the seriesof time relays A, B C, D E and F one for each group of runner motors,and a series of relays A", B C D E and F The time relay A and the relayA together control the operation of the motor A of grinding machine A,(Fig. 5*) or if A is a. group of 12 or more grinding machines, then therelays A and A control all the members of the group. Similarly, therelays C and C control the operation of the motor or group of motors G,as shown in Fig. 5.

The multiple switch P (Fig. 8) is similar to the switch M abovedescribed. It comprises a solenoid bar 60, operating the switch arms 61to 66 and yieldingly pulled to the right by the spring 68. The bar ismoved to the left to close the arms by the coil 69. The coil 69 isoperated by alternating current from the transformer coil 212. Thiscircuit, including the coil 69, passes through the arm 49 of the switchM, so that the energizing of the coil 69 and the closing of the switcharms 61 to 66 is dependent upon the closing of the switch M, which, asabove explained, occurs only after the start button K is pushed down. Itfollows that the actuation of the time relays A to F and the starting ofthe runner motors A to F must be preceded by the closing of the multipleswitch P, all of which appears in detail after the following briefdiscussion of the remainder of the control apparatus.

The six time relays which are closed after, and due to the closing ofthe multi 1e switch P, are all similar to the relay shown in Fig. 9.This relay comprises the arm 70 pivoted at 71 and having the contactends 72 and 73 adapted to engage the contacts 74 and 75 when the armswings to the right, the solenoid bar 76 connected to the arm 70 bythespring 77, the coil 78 for pulling current is supplied to themotor andto the coil 78 before the arm 70 closes, is regulated by the position ofthe arm 83, which can be held in any osition of circumferentialadjustment by t 1e thumb screw 86 or any other suitable means. Whencurrent is supplied through the wire 87, it passes through the coil 78to the return wire 88.- It may be here interpolated to avoid confusionthat the wires 87 and 88 are in the alternating current circuit,including the winding 69 and that the wire 88 also carries directcurrent. The current through 87 divides at the point 89 and passesthrough the circuit 90 to the motor and back to 87 at the point 91, viathe contact 92, which engages the arm 93 pivoted at such point 91. Thecoil 78 and motor are thus energized when current flows through 87, andthe disc 81 with the arm 83 begins to rotate. When the time elapses forwhich the relay is set, thearm 83 engages and trips the latch.84, andthe spring 77 placed under tension by the solenoid bar 76, pulls the arm70 to the right so that the contact ends 72 and 73 engage the contacts 74 and 75, thus establishing acircuit between the wires 88 and 94, thewire 88, as above stated, being the lead-in wire carrying directcurrent. The wire 94 leads to the relay A (Fig. 11) and serves to closethis relay, as later described, so as to cause the actuation of thestarter of the motor A. The movement of the arm 70 to the right breaksthe circuit between 92 and 93, so that the operation of the motor 80 isstopped after the arm 70 is moved to closed position. When the circuitbetween 87 and 88 is broken, the spring 79 will move the parts back tothe position shown, the arm being engaged and locked in open position bythe latch 84. When the circuit through the coil 78 is interrupted,automatic means, not shown, move the worm 82 out of engagement with theworm wheel 81, and a spring returns this wheel and the arm 83 tostarting position, as shown. This time relay is standard equipment,known in the art, and, therefore, not illustrated in all its details.

The closing of the relay A as just described, controls the operation ofthe relay A, such relay closing so that direct current is permitted toflow through the relay and to the starter of the motor A. This relay Awill be understood by referenceto Fig. 11, wherein 94 is the inlet wirefrom the relay A (Fig. 9) above referred to and 95 is the return wirethrou h which the current flows back to the negative side of the DCgenerator after passing through the coil 96. This causes the contactarms 97 and 98 ivoted at 99 and 100 and connected to the so enoid bar101 to swing to the left against the tension of the spring 102, engagingthe contacts 103 and 104. This com letes a circuit from the line 88through t e arm 97, contact 103, line 105 and coil 106 back to the line95, so that the contact arm 107 is swung to the left against the tensionof the spring 108 by the solenoid bar 109, causing the arm to engage thecontact 110. This completes a circuit from the positive line 88 to theline 111, which supplies current to the starter of the motor A andcauses the operation of such starter, as later described. The movementof the arm 98 to the left also breaks the contact between such arm andthe contact 112 at the terminal of the line 113, so that current to suchline which had up till this time been supplied from the line 88 is cutoil'. The line 113 also leads to the control apparatus of the motor andfunctions in connection therewith, as later described.

The starting panel S for the motor A is controlled from the line 111('Fig. 10) completed by the closing of the arm 107, and includes amultiple relay switch T similar to the multiple relay switch of Fig. 7.It 1ncludes a series of switch arms 114 to 118 operated by the solenoidbar 119 and adapted to engage, when closed, the contacts 120 to 124. Thebar is held yieldingly to the left by the s ring 125 and is moved to theright to close t 1e switch arms 114, 116, 117 and 118 and to 0 en thearm 115, when the coil 126 is energized. The closing of the arms 114,116 and 118 completes thecircuits to the motor A, while the openin ofthe arm 115 breaks the circuit through t e magnet coil 1,

which holds the air valve open, so that the energizing of the coil 126and the moving of the bar 119 to the right results in the starting ofthe motor A and the release of the air from the cylinder 27, permittinthe runner to move down by gravity and engage the lass. The members 0,0, 0 are thermal reay switches lying in the circuit, which energizes thecoil 126, such switches being 0 ened by the heating coils p p, p in thet ree lines of the circuits of the motor A, the principle of operationof these switches and their functions corresponding to those of theswitch N, heretofore described.

Other apparatus used in connection with the grinding unit A, and thecontrol panel S, as just described, are (see Fi 5") the switches 1' ands, the safety switch IT, the watt meter V, the start button W, the stopbutton X, the up and down switch Y and the slow drop out relay Z. Theswitches r and s are arranged so as to be closed when the runner reachesits u per limit of movement and to open when t e runner starts down fromits upper position. The switch 1' lies in the circuit including the coil126 ofthe multipleswitch T, so that the motor A cannot be started unlessthe runner is in its upper position. The switch 0 lies in a circuit,which short circuits the watt meter V, so that the watt meter isprotected a ainst the heavy current flowing throu h t e motor circuitwhen the motor is -tart1ng. When the motor moves down, the switches rand a open. Fig. 6 shows the switches r and s in detail. The switch armsare held in en agement with the contacts 127 and 128 by t e springs 129,which are attached to the crank arms 130 on which the switch arms aremounted, the crank arms being pivoted at 131. A pair of depcndin rods132 engage a plate 133 lying beneath t e lever arm 12, which su portsthe runner. When the runner moves own, thus allowing the plate 133 androds 132 to move up, the springs 129 cause the arms r and s to move awayfrom the contacts 127 and 128. When the runner moves up again, the rods132 are moved down, closing the switch arms. In order to permit theclosing of the switch arms by hand when the runner is down, thedependent chain 134 is rovided. This would permit the starting of t emotor with the runner in lowered position and would short circuit thewatt meter at such starting time. i

The safety switch U when in the position shown completes the circuitthrough the coil 126, which closes the multiple switch T. If this switchis moved down and breaks this circuit, it is im ossible, therefore, tostart the motor A. his switch is designed to be operated by a key and islocked in open position when re airs or other work is being done of sucha cliaracter that the accidental starting of the motor would endangerthe workmen.

The stop and start buttons X and W are of the type which are yieldinglyheld in the positions shown and return to such positions after the ocrating pressure is released. As later descri d, t se buttons with theirconnections permit t e stopping and starting of the motor A independentof the rest of the runner motors B to F. Similarly, the switch Y may bemoved from the open posit-ion shown to closed position to cause therunner of the independent of all the other runners and may then be movedback to the position shown to cause the unit A to move down again togrinding position, this being accomplished grinding unit A to move upwithout stopping the rotation of the runner.

11 3 leading from the re ay A,

potential coil were supplied with three phase current. This is a matterof considerable economy because each of the seventy odd surfacing unitsinthe system must be provided with its own watt meter to indicate theamount of work which each runner is doing. The slow drop out meter Z hasits coil -141 energized by current su plied from the line l and thiscoil acts to pull the solenoid bar 142 to the ri ht against thetensionof the spring 143, so t at the arm 144 engages the contact 145 until thecircuit from 113 is broken by the move-' ment of the arm 98 of. therelay A to the left. The relay is of the slow drop out type, so thatafter the circuit through the coil 141 is broken, the arm 144. remainsclosed: long enough to permit the arm 107 of the relay A to be closed,and for the current thus supplied from the line 111 through the coil 126of the multiple switch T and through the arm 145 to close such multipleswitch I T, the purpose of this arrangement appearing later inconnection with the description of the operation.

Direct current is supplied to the system from the lines 146 and 147, and148 and 149 past the switches a and b. This current is utilized inoperating the coil'52 of the mul-. tiple switch M, the coil 126 of themultiple switch T; and the coils 96 and 106 of the relays A to FAlternating current is supplied from the transformer w1ndi ng 212 foroperating the coil 69 of the multiple switch P, the coil 150 of thecontact ma ing voltmeter 0 (later described), the coils 78 of the timerelays A to F", and the motors of such last relays.

The main supply of three-phase alternating current is supplied from thebuss lines 151, 152 and 153. In order to operate the watt meters on arelatively low volta e, so that chea er instruments may be emp oyed, thetrans ormer 154 is used, which gives the desired reduced voltage on thelines 137, 138, 139 and 140, heretofore referred to, in connection withthe watt meters V. All of the runner driving motors, including A and Care supplied from the lines 151, 152 and 153 by the lines 155, 156 and157 and 158, 159 and 160, respectively, while the table driving motors Gand H are supplied by the lines 161, 162 and 163, in which lines arelocated the switches e and f, the latter switch having connected to workwith it the switch arm 9 lying in the direct current line, whichenergizes the coil 52 of the multiple switch M. A number of other handoperated switches h, h, h are also located in the same direct currentline, and located at intervals along thelength of the line of surfacingunits. By opening any one of these, the circuit through the operatingcoil 52 of the switch M is interrupted and this results in the stoppingof the table drive motor G and of all the runner drive motors A to F'-and the raising of the runners driven thereby. These are emergfncyswitches, as they rovide for the quic stopping of all of the rivingmotors from any point along the system in case of accident. They, areshown as double, the right hand side of each switch controllin r asecond direct current .circuit 165, whic in turn governs'equipment .onanother panel duplicating that of the panel J and includin a multipleswitch similar to the switch .This other switch," when c'lose'd,completes the circuits from the source of alternatm current to theduplicate drive motor H. Tiis is an obvious matter of duplication in thewiring arrangement and is, therefore, omitted, no claim being made tothe feature of using a duplicate table drive motor, as this is a commonexpedient in other relations for adding to the certainty of operation.

The. motor G is provided with a watt meter i, which like the watt'meterV has one terminal 166 of its potential coil connected to the neutralline and the other terminal 167 connected to one of the otheralternating current supply lines 139. The contact making volt meter 0(Fig. 5) whose coil lies in the alternating current line from thetransformer winding 212, serves to cause a lifting of the runners andthe interruption of the current supply to the runner motors. The coiloperates the solenoid bar 168 pivoted to the contact arm 169, which isnormally held closed by the coil acting upon the solenoid bar. When thepotential in the AC lines 151, 152-and 153 drops below a certain point,a corresponding decrease is registered in the transformer winding 212,and the tension spring opens the contact arm 169, and interrupts the ACcurrent through the coil 69 of the multiple switch S, so that suchswitch opens and results in the cutting off of current to the runnerdriving motors in timed sequence (through the intermediary of the timerelays) and in the raising of the runners. When the volta e rises again,the arm 169 closes again, and t e time relays are actuated in sequenceto again securea flow of current to the runner motor, to which thecurrent flow has been discontinued, all of which is more-fully set forthin the description of the complete operation which follows.

The wiring diagram of the connections for the motor G (Fig. 5) disclosesa pilot motor transformer j, a split field pilot motor is and a pilotmotor limit switch Z, which in connection with the slow and fast buttons0 and p and the switch arm 50 of the switch M, control the speed of'themotor G, but no description of these parts or their functioning isregarded as necessary, as they involve standard equipment well known inthe art and have nothing to do with the present invention, the showingin the drawings of slow drop out relay these parts being included merelyto make the wiring diagram complete.

In starting the operation of the system, the hand 0 rated switches areall closed, and it Willa assumed that all of the runners are in upperosition, the switches r and a are closed, tii e push buttons are allspring held in the positions shown in Figs. 5, 5 and 5", none of themotors of the system are operating, and all of the coil operated relayswitches are 0 11, except that of the i The coil 141 of such relay Z isenergized at this time by direct current from. the line 146 through theline 88 to the relay A (Fig. 11) through the arm 98, the line 113 andthe lines 171 and 172 to 0 negative return line 173. The operation isstarted by ressin down the start button K of the pane J, an holding itdown until light shows in the lamps 173, after which the button may bereleased,

Bermitting it to return to open position.

irect current flows to the button contacts from the line 146 through theline 174, past the contacts'of the buttons K and L, through a furthersection of the line 174 to the coil 52, through' a further section ofthe line 174 to switch 9, through a further section of the line 17 4 tothe switch N, through this switch and the further sections of-the line174 leading past all the emergency switches h and back to thenegative'side of the switch a. The coil 52, thus energized causes theswitch M to close, thus completing the three circuits 175, 176 and 177leading from the AG lines 161, 162 and 163 to the table drive motor G,such current flowing through the contact arms 45, 46 and 47 (Fig. 7),the circuit 175 passing through the current coil of the watt meter Theother table drive motor is similarly started at the same time by currentthrough the line 165, heretofore referred to, which is in parallel withthe line 174 and passes to a planel, which includes equi ment similar tot at of the panel J.

T e closing of the switch M also completes another .circuit due to theclosing of the arm 49, such circuit including the AC transformer winding212 and the closing coil 69 of the multiple switch P. This circuit isdesi ated as 178. Starting with the right han end of the transformercoil 70, it includes the section 178 leading to the point 179,thefurther section 178 lea from 179 to the arm 49, the further section178 leading to the int 180, coil 69, section 178, arm 169 an wire 88 topoint 181, and section 178 to the left hand end of the transformer coil212. At this time, the arm 169 of the relay 0 is closed, as its coil 150is ener 'zed by alternating current from the win 212. The coil 69 nowcloses the switch g, including the arm 61, so that alternating currentfrom the point 180 asses through such arm to the line 87, and oncethrough the time relay A and back to the oint 181 and winding 212 viathe line 88.

he actuation of this relay has been described in connection with Fig. 9,the current from the line 87 passing through the coil 78 and thewindings of the motor 80, so that the sprin 77 is placed in tension andthe arm 83 driven from the motor trips the catch 84, after aredetermined interval of time, the arm 70 t en being swung to the rightby the spring 77, so that the contact ends 72 and 73 engage the contacts74 an 75, thus completing the circuit between the lines 94 and 88.Direct current now flows from the line 88 to the line 94 via the arm 70and thence through the -coil 96 of the relay A from which it returns tothe negative line 147 via the line 95. This causes the arm 97 to swingto the left so that direct current from the line 88 flows through sucharm, the line 105 (Fig. 11), and the coil 106, to the negative returnwire 95. The flow of current throu h the coil 106 closes the arm 107, so

that 'rect current from the positive line 88 flows through the am 107 tothe point 183.

From the point 183, the current from the line 88 makes two circuits, oneof which flowing through the line 111 energizes the operating coil 126of the multiple switch T as later described), while the other passes trough the line 185, the resistance 186, section of line 185, arm 48,section of line 185, contacts of stop button L, section of line 174,coil 52, section of line 174 switch g, section of line 174, switch N,and line 174 leading past the switches it back to the negative line 147at switch a, as heretofore described. This provides a second or holdingcircuit through the coil 52, so that, when the button K is released,breakin the circuit at this oint, the switch M wifi still be heldclosed.

his circuit also provides for lighting the lamps 173, as theselights'are in shunt with a part of the circuit. Starting at the switchN, this shunt circuit includes the section of line 185 to the right ofthe switch N, the lam s 173" and the section of the line 185 lea mg tothe end of the resistance 186. The lighting of the lam s 173 therefore,indicates the time when e holding circuit 185 is completed b the closingof thecontact arm 107 of t e relay A'-, so that the contacts of safetyswitch button U, and section of line 111. to negative return line 173.The contact arm of the relay Z was held closed long enough to permit theenergizin of the coil 126, due to its slow openingc aracterist-ic, thecoil 141\having its current from its suppl circuit 171 cut 011', as soonas the arm 98 o the rela A, moved to the left under the influence o thecoil 96, breaking the circuit from the line 88 to the line 113. Thecurrent, as thus briefly supplied to the coil 126, moves the switch T toclosed position. The closing of the arm 117 of the switch T establishesa new circuit through the coil 126, which acts as a holding circuit,after the other circuit through the coil 126 is broken at the slow dropout relay Z. This circuit comprises the section pf heavy, the coils ofthe thermal relay swithl-ie's' line 111 leading to the ush button X,line 186, arm 117 of switch section of line 186, coil 126, section ofline 111, thermal relay switches o, o, 0, section of line 111, button U,and section of line 111 back to negative line 173. The switch T is thusclosed and held closed, after the relay Z opens, and this circuit ismaintained after the switches 1' and s are opened by the downwardmovement of the runner, as the holding circuit, as above described, doesnot. pass through these switches. I p

The closing of the switch T completes the three circuits 155, 156 and157 through the contact arms 114, 116 and 118 and through the windings.of the motor A, so that the rotation of the motor and the surfaingrunner starts upon the closing of the switdh.

In case the load on these circuits becomestoo and.

0, o, heat up and open the switchis and break the circuit through theline} coil 126, so that the switch T opens.

At the time the motor A is thus started and while in upper position, theswitch a short circuits the line 157, which passes through the currentcoil of the watt meter V, so that at this moment of high load, when themotor is starting, the watt meter is relieved of this current, whichflows from one section of the line 157 to another section thereof viathe line 187 and switch a.

The closing of the multi le switch T also results in the lowering of t emotor A and its runner carried by the arm 12. This is caused by theopenin of the'arm 11-5 of the switch T (Flg. is moved to the right bythe coil 126. This interrupts the circuit 187, 187 from the line 188back to the line 173 through the winding I, so that the valves 39 and(Fig. 4) are moved to the positions of Fig. 4 by the spring 41, thuscutting off the supply of air to the cylinder 27 and permitting the airtherefrom to exhaust through the passage 31 and opening 43. As a result,the arm 12 and the runner 11 carried thereby begin to move as thesolenoid bar switches r an s. The opening 0 the switch r interrupts theclosing circuit of the switch A T through the coil 126, so that only theholding circuit through such coil remains effective, while the o eningof the switch a directs the current 0 the motor circuit line 157 throughthe watt meter V, so that from this. time -on the watt meter registersthe current used by the motor A. a

11' itnow becomes necessary to stop the motor A and lift-the runnerindependent of the rest of the system, this can be done by pushing thestop button X, which interrupts the holding circuit fiowin through thelines 111 and186 and thecoi 126 of the switch T, so thatsuch switchopens, breaking the motor circuits 155, 156 and 157 and closin the arm115 so that the winding of the coil I is energized and the runner islifted. After the button X is released and moves back to closed sition,the switch -T still remains open, since the holding circuit through the0011 126 has been opened by the fin er 117 ,and since the closingcircuit throu the relay Z is now broken at such rela he motor can bestarted and lowered, however, by closin the start button W, which comletes the closingcircuit through the coi 126, so that the switch T is ain closed and the circuit throu h the coil I is broken. 1 11811101301,there ore, starts. again and the runner is lowered, and this conditionis. continued after the button .W is released and opens, since theholding circuit past the button X and through the lines 111 and 186 isagain made efi'ective.

In case it is desired to raise the runner 'and lower it again withoutstopping the rotation of the runner, this is accomplished 187, t ewinding I, through a section of the line 187 passing a ta connection onthe safety switch U, throng a section of the line 187 to a tap 190" onthe line 189, through 7 a section of the line 189, through the contacts191 of the switch Y (now assumed closed), through the lines 192 and 172to the negative bus 173, and the winding I thus being ener zed, therunner moves up. When the switc Y is moved back to the position shown,this breaks the circuit through the winding I, so'that the runner againmoves down. i I f I The surfacing unit A is thus under independentcoritrol, so that the runner maybe moved up or down or sto ed or startedas desired. This unit, as W5 as all the other units may now be stoppedfrom the master control panel J. This is accomplished by pressing downthe stop button L. This interrupts the holding circuit through the'coil.

52, as heretofore described, so that the multiple switch M opens,breaking the three circuits 175, 1 76 and 177 through the table drivemotor G at the contact arms 45, 46 and 47, so that this motor stops. Theopening of the switch M also breaks the alternating current circuitthrough the arm 49, so that the circuit- 178 leading through the coil 69of the switch P (Fig. 821 is interrupted and such switch opens. T eopenin of the arm 61 interrupts the circuit 8 through the coil 78(F1g.9) of the time relay A so that the spring 77 opens the switch arm70. The opening of this arm interrupts the circuit 88, 94 to the coil 96and return line 95, so that the switch arms 97 and 98 open to theposition of Fig. 11, thus interrupting'the circuit from the line 88 to te return line 95 via the arm 97, wire 105, 0011 106 and wire 105. Thispermits the arm 107 to open,-interrupting the circuit through the line111.

Q! As heretofore explained, the circuit 111 is the one throu h whichcurrent flows to the coil 126, whic holds the multiple switch T closed,so'that when this circuit is interrupted, the switch opens, interruptingthe,

three circuits 155, 156 and 157 of t e runner driving the motor A andcloses the circuit through the magnet winding. The rotation of the motoris, therefore, stop ed and the runner is raised by the air c lin er 27.The movement of the arm 98 o the relay A to its original position, asillustrated, again com letes the circuit through the coil 141 of t eslow drop out relay via the lines 113 and 172, so that the arm of thisrelay is closed, placing the arts in their original position, asdescribed in the beginnin and so that the starting of the motor A may beaccomplished by )ressing the start button K, as heretofore escribed. Theupward movement of the runner supporting arni 12 also closes theswitches r and s, so that the motor can be started in its upper positionand so that the watt meter V is short circuited during such startingmovement. The fast and slow buttons p and 0 (Fig. 5) operating inconjunction with the pilot motor In control the speed of rotation of themotor G, and the arm 50 of the switch M, which is normally closed,insures that in starting the system, the motors will operate at slowspeed until the fast button P is rcssed down.

The foregoing sets forth t e operation involved in starting only one ofthe motors of the group to which t e runner motor A belongs. It will beunderstood that the wiring and control apparatus for each of the othermotors of the group is the same, direct current being supplied to suchother from the relays A and A. The control of the other groups B to F issimilarly affected through the relays B to F and B' to F, the relays Bto F being adjusted so that they close in sequence one after the otherafter A closes. For instance, the arm of the relay B ma' be set to closeonethird of a second a ter the arm 70 0f the relay A closes and theother relays C to F will similarly close in uence at intervals oftwo-fifths of a secon The grou s of runner driving motors will,therefore, lie

'- started in sequence at intervals of one-third of a second thusdistributing the load upon the supply line 151, 152 and 153.

The manner in which another group of motors C areconnected to the s stemand operated from the relays C and is illustrated in Figs.' 5 and 5".Here the closing of the arm 107 is accom lished in the same manner asthe closing 0 the am 107, heretofore described, and the closing of thisarm secures the supply of direct current from the line 88 to the line111', such line corresponding to the line 111. Similarly, direct currentpassing through the relay C is 'sup lied to the line 113', such linecorres n ing to the line 113, heretofore descri The line control of therunner motor C and the functioning of the appsratus associated therewithmerely duplicates that for the motor A and the operation is obviouswithout further description or explanation, the reference numerals andletters employed being the same as for the motor A, except in theapplication of the prime mark to eachof such numerals and letters. Theother rela s B, D, E and F and B,

.D', E and I control the contact arms 107?, 107', 107 and 107 from whichthe lines 111, 111', 111 and 111 are supplied with direct current andlead to the other groups of runner motors B, D, E and F in the samemanner as illustrated for the lines 111 and 111'. Similarly, the lines113 113 113 and 113 correspond in function to the lines 113 and 113', intheir control of the several slow drop out relays corresponding to therelays Z and Z.

The contact making voltmeter c functions in connection with the switch Pto cause the runner driving motors tobe disconnected from the powerlines in groups in regular sequence with a definite time interva betweengroups in case of a failure of the alternating current su ply. Further,the arrangement is such t at should the failure of the alternatingcurrent power supply be just a dip of voltage and of ver short duration,so that the voltage is bac on the line before the sequence is completedthe groups remaining on the line stay on, and the groups that have beenout 01f are members of the group by the lines 111, 113,, again startedin their regular order with a 173 and 188, so that the group iscontrolled definite time interval between groups III The coil 150 isenergized from the winding 212 of the transformer which is operated fromthe alternatin current power lines 151, 152 and 153, so t at the voltagethrough the coil 150 fluctuates with that in the power lines. In case ofa failure of the power supply, the voltage in the coil 150 drops and thespring 170 opens the contact arm 169, thus interrupting the currentthrough the coil 1S different. In such case, although all of .thecontact arms 70 0 en immediately, when the switch P o ens, t e openingof the arms 107, 107, etc. 18 delayed and occurs in time The firstcontact arm of the series 107, 107, etc. which opens upon theopening ofthe contact arms 70 is the arm 107. This is not instantaneous upon thebreaking of the circuit through the coil 96, as the residual magnetismin the coil prevents the arms 97 and 98 from instantly moving to theright. During this interval of delay, current continues to flow through.the coil 96 of the next relay B from the line 88 via the arm 98 andline 190, so that until the arm 98 opens, the current continues to flowthrough the coil 96 and the residual magnetism in this coil 96' thenkeeps the arms 97' and 98' closed a definite interval after the arms 97and 98 open. As a result, the arm 107 opens at a definite period afterthe arm 107. Similarly, the arms of the other relays C to F open atsuccessive spaced intervals. In case the voltage is restored in thepower circuit when only a part of the arms 107 to 107 have opened, thecontact arm 169 of the voltmeter c closes followed by the closing of theswitch P. If only the first two of the relays A and B have opened theirarms 107 and 107 when this occurs, the rest of them will not open up,since a flow of current is restored throu 11 their coils 96 t6 96 due tothe closure of t e arms 63 to 66 of the relay P. For instance, theclosing of the arm 63 permits a flow of current through the coil 96'from the line 88, via such arm 63, and the line 191. The closing of thearms 64, 65 and 66 performs a similar function with relation to thecoils 96 to 96 of the relays D E and F The supply of current is -nowrestored to the runner motors of the groups A and B, due to the closingof the arm 61 of the switch I, the operation being the same asheretofore described in connection with the preming of the start buttonK, namely, the arms 70 of the relays A and B close in timed sequence,followed by the closing of the arms 107 and 107 A Fig. 12 illustrates amodification involving the use of a different form of prime mover forswinging the lever arm 12, which su ports the motor and runner. In thismodification, the prime mover is an electric motor which operatesthrough a worm and threaded shaft to raise and lower the arm 12. Directcurrent is employed to operate the motor and the control system is verysimilar to that described-inconnection with the apparatus using the aircylinder as the prime mover for controlling the up and down movement ofthe arm 12, and the parts carried thereby.

Referring to the drawing, the arm 12 carrying the meter G and therunner, has pivotally mounted in its outer end, the block 195, throughwhich is threaded the operating shaft 196, carrying at its up or end aworm wheel in the caslng 197. I his worm wheel is driven by a wormcarried by the shaft 198, and this shaft is driven from the motor 199through the intermediary of the gears 200 and 201 carried respectivelyby the motor shaft and the shaft 198. The motor 199 is of the splitfield type arranged so that current from the line 202 passing throughthe coil 203 and line 204 rotates the motor in a direction to lower therunner, while current from the line 202 passing through the coil 205 andline 206 rotates the motor in a direction to raise the runner.

The motor G is driven from current supplied by the lines 158, 159 and160 and these circuits are controlled by the switch T having the closingcoil 126 and similar throughout in construction to the switch T. Thecoil 126 is energized by direct current supplied from the line 111",this circuit corresponding to the circuits 111 and 111 of Fig. 5 thecontact arm 144" of the slow drop out relay Z being held shut at thistime b current supplied from the line 113 through the line 171". Afterthe switch T is closed, a holding circuit is established through the arm117 via the lines 111, 186, 111, switch U and section of line 111, sothat after the circuit through the line 111 is broken b the opening ofthe switch 7-, the switc T will still remain closed, subject tointerruption when desired b pressing the stop button. A limit switch 207is provided in the line 206, such switch being opened by suitable means(not shown) when the runner approaches its upper 1 osition and beingclosed again automatical y when the runner starts down.

If the runner is in its lower position and the current supply to thecoil 126 is cut off,

permitting the switch T to open, such 0 ening closes the arm 115 so thatcurrent owe to the motor 200 from the line 202 and back to the ne ativeline 173, via the following circuit ine 206, arm 115", line 208, arm Uand section of line 111. This causes the motor to rotate so as to raisethe runner, such movement continuing until the limit switch 207 isopened automatically as the runner reaches its u ward limit of movement, thus causing t e motor to stop. In order to cause the motor 200 torotate in the reverse direction to move the runner down, it is necesarto ress in the button Y". This completes t e circuit from the positiveline 202 through the motor and back to the negative line 17 3 via thefollowing connections:line 204, switch arm U, line 204,

contacts 208- of switch Y, line 204, switch arm U and line 111. Thebuttons Y and Y are connected together and spring controlled, so thatwhen either button is released, from manual pressure, the buttons returnto the neutral position shown. The buttons Y is, therefore, releasedwhen the motor 202 has rotated sufliciently to lower the runner tosurfacin position. The motor may now be cause to 0 rate to raise therunner by Y. The arm 115 0 the switch T" is now open, but the up circuitthrough the line 206 back to the negative line 173" is completed fromthe point 209 via the line 210, the contacts 211 of the button Y, andthe line 204.

The motor G may be stopped and the runner lifted by pressing the stopbutton X and may be started by pressing the start button W, the pressingof the button X? serving to interru t the holding circuit 186 to thecoil 126, w ile the pressing of the button W completes the closingcircuit 111 through such coil.

What I claim is:

1. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable driven runner,supporting means for carrying a series of sheets of material to besurfaced continuously beneath the series of runners, a prime mover ateach machine adapted to raise the runner thereof out of contact with thesheets carried upon the supporting means, an electric motor for drivingsaid supporting means, a power circuit for suppl ing current to saidmotor, and means, includin a relay governed from said ower circuit, forsecuring the actuation 0 said rime movers to lift the runners upon aailure of the power supply to said circuit.

2. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for sup lying currentthereto, su porting means or carrying a series of s eets of material tobe surfaced ressing in t e button continuously beneath the series ofrunners, a prime mover at each machine adapted to raise the runnerthereof out of contact with the sheets carried upon the supporti means,an electric motor for driving sai supporting means, a power circuit foran plying current thereto, and means, inclusmg a relay governed from thepower circuit, for cutting olf the supply of current to the runnerrotating motors, and for securing'the actuation of said prime movers tolift the runners upon failure of the power supply to said circuit.

3. In apparatus foroontinuously surfacing sheets of material, a seriesof surfac' machines, each having a vertically movable driven runner,supporting means forcarrying a series of sheets ofmaterial to besurfaced continuously beneath the series of runners, a prime mover ateach machine adapted to'raise the runner thereof out of contact with thesheets carried upon the supporting means, an electric motor for drivingsaid. supporting means, a power circuit for supplyin current to saidmotor, and means, mclu ing an automatic switch governed by said powercircuit and relay means, for securing the actuation of said prime moversto lift the runners in case the current flow through said motorincreases beyond a predetermined point.

4. In apparatus for continuously surfacing sheets of material, a seriesof surfacin machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for supplying currentthereto, su portin means or carrying a series of sli eets 0 material tobe surfaced continuously beneath the series of runners, a prime mover ateach machine adapted to ralse the runner thereof out of contact with thesheets carried upon the supportin means, an electric motor for drivingsai supporting means, a power circuit for supplying current thereto, andmeans, including an automatic switch governed by said power circuit andrela means, for securin the actuation of sai prime movers to li therunners and to cut off the flow of current to the runner rotating motorsin case the current flow through said motor for moving the supportingmeans for theglass increases above a predetermined point.

5. In apparatus forcontinuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for supplying currentthereto, supporting means for carr ing a se-- ries of sheets of materialto be sur aced continuously beneath the series of runners, a prime moverat each machine adapted to raise the runner thereof out of contact withthe sheets carried upon the supporti means, .an electric motor fordriving sai supporting means, a power circuit for supplying currentthereto, a relay for each machine for controlling the flow of current tothe runner rotating motor and to said prime mover for controlling itsoperation, a master relay for controlling all of said relays, and alsothe flow of current to the motor which drives said supporting means, amanual control for said master relay, and still other relay means alsocontrolled from the master relay and from said power circuit andarranged to open and cause the opening of the first relays and theactuation of the prime movers to raise the runners upon a failure of thepower supply to said power circuit.

6. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for supplying currentthereto, supporting means for carrying a series of sheets of material tobe surfaced continuously; beneath the series ofvrunners, a prime moverat each machine adapted to raise the runner thereof out of contact withthe sheets carried upon the supporting means, an electric motor fordriving said supporting means, a power circuit for supplying currentthereto, a relay for each machine for controlling the flow of current tothe runner rotating motor and to said prime mover for controlling itsoperation, a master relay for controlling all of said relays, and alsothe flow of current tothe motor which drives said supporting means, amanual control for said master relay, and an' automatic switchcontrolled by the flow of current to the motor which moves saidsupporting means and adapted, when such flow rises above a predeterimnedpoint, to open and cause the opening of said master relay, which in turncauses the opening of the other relays, cutting oil the supply ofcurrent to the runner rotating motors and causing the actuation of theprime movers to raise the runners.

7. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for supplying currentthereto, supporting means for carrying a series of sheets of material tobe surfaced continuously beneath the series of runners, a prime mover ateach machine adapted to raise the runner thereof out of contact with thesheets carried upon the supporting means, an electric motor for drivingsaid supporting means, a power circuit for supplying current thereto, arelay for eachmachine for controlling the flow of current to the runnerrotating motor and to said prime mover for controlling its operation, aseries of time relays adapted to close in sequence after actuatingcurrent is supplied thereto and controlling said first relays, a masterrelay controllin the flow of actuating current to the time re ays, andalso the flow of current to the motor, which drives said glass suporting means, and a manual control for sal master relay, said relays foreach machine being arranged, when closed from the master relay, tosecure aflow of current to the runner drive motors, and to cause theactuation of the prime movers tosecure the lowering of the runners, andwhen opened from the master relay, to cut off the flow of current to therunner drive motors and to cause the actuation of the prime movers tsecure the raising of the runners.

8. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having-a vertically movable runner, anelectric motor for rotating each runner,'and means for supplying currentthereto, supporting means for carrying a series of sheets of material tobe surfaced continuously beneath the series of runners, a prime mover ateach machine adapted to raise the runner thereof out of contact with thesheets carried upon the supporting means, an electric motor for drivingsaid supporting means, a power circuit for supplylng current thereto, arelay for each machine for controlling the flow of current to the runnerrotatin motor and to said prime mover for control ing its operation, aseries of time relays adapted to'close in sequence after actuatlngcurrent is supplied thereto and controlling said first relays, a masterrelay controlling the flowof actuating current to the time relays, andalso the flow of current to the motor, which drives said glasssupporting means, a manual control forsaid master relay, and meansgoverned from the power circuit for causing the opening of the timerelays upon a failure of the power supply to said power circuit.

9. In apparatus for continuously surfacing sheets of material, a seriesof surfacing machines, each having a vertically movable runner, anelectric motor for rotating each runner, and means for sup lying currentthereto, supporting means fbr carrying a series of sheets of material tobe surfaced continuously beneath the series of runners, a prime mover ateach machine adapted to raise the runner thereof out of contact with thesheets carried upon the supporting means, an electric motor for drivingsaid supporting means, a power circuit for supplying current theretoearelay for each ma chine for controlling the flow of current to therunner rotating motor and to said prime mover for controlling itsoperation, a series of time relays adapted to close in sequence afteractuating current is supplied thereto and controlling said first relays,a master relay controlling the flow of actuating our-

